>>1
Foreskin got nothing to do with pleasure; Clit has everything to do with it. Women can't have the best orgasm possible without it. Foreskin is no different from the skin on your balls or on your ass or your face, it's just skin like the rest.
And the overarching reason for it is control. The vulva is usually stitched shut in such practices and reopened for the woman's husband to fuck her, before it's restiched shut. This results in only excessive pain for the woman, no pleasure.